Question

7. What purpose does the ECG serve? It is determined that Ms. X. has a large infarct in the anterior left ventricle. 8. Ms. X. is showing increasing PVCs on the ECG. State the cause and describe the effect if these continue to increase in frequency 9. On day 6 after admission Ms. X is preparing to go home with her son and they receive instructions on lifestyle modifications that are desirable if Ms. X is to avoid another MI. What measures should be included in such a discussion?

Answer 1

7).

The electrocardiograph is an instrument used to record the electrical activities of the heart. The graph obtained by the electrocardiograph is called electrocardiogram (ECG). In this, a needle electrode is used to record the electrical activity of the cardiac muscle. Some of the diseases that can be diagnosed using ECG are ischemia, myocardial infarction, or fibrillation.

The electrical events are denoted with the letters P, Q, R, S, and T; these are called electrical waves. The significance of the electric waves in the ECG is given below:

ECG section	Heart activity
P wave	Atrial depolarization
P-R interval	The time between atrial contraction and ventricular contraction
QRS complex	Depolarization of the ventricles
ST segment	The time between ventricular depolarization and the initiation of repolarization
T wave	Ventricular repolarization
Q-T interval	The time between ventricular depolarization and completion of repolarization

Infarct in the anterior left ventricle is likely to cause premature ventricular contractions, which shows irregular heart rate.